Back to Saturn X

Back to Saturn X is a series of megawads for Doom II, designed to be compatible with DOOM2.EXE. Created by the Back to Saturn X Team, it features an exclusive texture set, original music, and a new palette and colormap.

Song and album titles from provide the title, episode names, and map names. Titles and song lyrics are incorporated into the text screens as well.

The first episode was originally released on December 10, 2012 for Doom's 19th birthday, featuring twenty regular levels, one secret level, and a recurring train station hub. An additional level was inserted in a later release on August 1, 2013. The first non-beta release was on February 27, 2017, and inserted another additional level. The episode received one of the 2013 Cacowards.

The second episode was beta-released on 1 September, 2014, with another twenty-two levels, a secret level, four episode hubs and an ending screen. It received one of the 2014 Cacowards. Its final version was released on August 14, 2020.

On June 25, 2020, the first episode was added to the list of official add-ons for the 2019 re-release of Doom II. This curated version replaces all the Guided by Voices-derived level names and its title is reduced to the acronym "BTSX Episode 1". The title screen was changed accordingly, and jokingly expands the title to "Better Texturing with Startan X". On August 14, 2020, Episode 2 received the same treatment with the joke subtitle of "Big Towers, Says Xaser".

The third and final episode remains in development. On August 10, 2023, a preview build was published containing five select maps from the episode, coinciding with QuakeCon.

Episode 1: Get Out Of My Stations

 * MAP01: Back to Saturn X Radio Report by Sarah Mancuso and Richard Frei
 * MAP02: Postal Blowfish by Kim Bach and Sarah Mancuso
 * MAP03: The Room Taking Shape by Paul DeBruyne
 * MAP04: A Good Flying Bird by Sarah Mancuso
 * MAP05: Total Exposure by Walker Wright
 * MAP06: Mix Up The Satellite by Trevor Primmett
 * MAP07: Metal Mothers by Björn Ostmann
 * MAP08: Get Out Of My Stations I (Episode Hub) by Sarah Mancuso
 * MAP09: Some Drilling Implied by Sarah Mancuso and Travers Dunne
 * MAP10: A Proud And Booming Industry by Paul DeBruyne
 * MAP11: The Colossus Crawls West by Ed Cripps
 * MAP12: Underground Initiations by Travers Dunne and Paul DeBruyne
 * MAP13: I'll Replace You With Machines by Sarah Mancuso and Paul DeBruyne
 * MAP14: Big Chief Chinese Restaurant by Matthew Edwards and Sarah Mancuso
 * MAP15: Tricyclic Looper by Brett Harrell
 * MAP16: Get Out Of My Stations II (Episode Hub) by Sarah Mancuso
 * MAP17: Navigating Flood Regions by Sarah Mancuso
 * MAP18: Cyclone Utilities (Remember Your Birthday) by Simon Judd and Sarah Mancuso
 * MAP19: Bingo Pool Hall of Blood by Richard Frei and Sarah Mancuso
 * MAP20: U.S. Mustard Company by Matt Cibulas
 * MAP21: Failed Experiments and Trashed Aircraft by Nick Laurent and Richard Frei
 * MAP22: Gonna Never Have To Die by Matt Cibulas and Paul DeBruyne
 * MAP23: Get Out Of My Stations III (Episode Hub) by Sarah Mancuso
 * MAP24: Tough Skin River by Tango
 * MAP25: The Unsinkable Fats Domino by Sarah Mancuso
 * MAP31: Optical Hopscotch by Paul DeBruyne
 * MAP32: The Hard Way by Paul DeBruyne

Soundtrack

 * MAP01: "Entering" by Sarah Mancuso
 * MAP02: "Phobophobe" by Sarah Mancuso
 * MAP03: "Drilling By Night" by Stuart Rynn
 * MAP04: "Clonk" by Sarah Mancuso
 * MAP05: "Atmospheric Pressure" by James Paddock
 * MAP06: "Nanonucleonic Cyborg Summoning" by Elric Sullivan
 * MAP07: "Conductor" by James Paddock
 * MAP08: "Waiting" by Sarah Mancuso
 * MAP09: "Untilted" by James Paddock
 * MAP10: "Coal" by James Paddock
 * MAP11: "Yaw" by James Paddock
 * MAP12: "Liquid Luck" by James Paddock
 * MAP13: "Escape Velocity" by James Paddock
 * MAP14: "24" by Stuart Rynn
 * MAP15: "Quicksilver" by James Paddock
 * MAP16: "Waiting" by Sarah Mancuso
 * MAP17: "Dirt" by Sarah Mancuso
 * MAP18: "Forget Your Name" by Simon Judd
 * MAP19: "Faultline" by James Paddock
 * MAP20: "The Cry" by James Paddock
 * MAP21: "Heliotrope" by James Paddock
 * MAP22: "Womp" by Sarah Mancuso
 * MAP23: "Waiting" by Sarah Mancuso
 * MAP24: "Within Reach" by James Paddock
 * MAP25: "Undersea" by Sarah Mancuso
 * MAP31: "Bitmap" by Sarah Mancuso
 * MAP32: "Atomic" by James Paddock
 * Ending screen: "Undersea" by Sarah Mancuso

Episode 2: Tower in the Fountain of Sparks

 * MAP01: Shadow Port by Josh Sealy, Sarah Mancuso and Boris Klimeš
 * MAP02: Underwater Explosions by Tango
 * MAP03: Wings of Thorn by Brad Spencer and Xaser Acheron
 * MAP04: Dirty Water by Mike Alfredson and Richard Frei
 * MAP05: Tower in the Fountain of Sparks I (Episode Hub) by Xaser Acheron
 * MAP06: Useless Inventions by Björn Ostmann
 * MAP07: Shrine to the Dynamic Years (Athens Time Change Riots) by Eric Baker
 * MAP08: A Blue Shadow by Matt Tropiano and Richard Frei
 * MAP09: Adverse Wind by Adrian Hanekom and Sarah Mancuso
 * MAP10: Eureka Signs by Sarah Mancuso
 * MAP11: Tower in the Fountain of Sparks II (Episode Hub) by Xaser Acheron
 * MAP12: Demons Are Real by Paul DeBruyne
 * MAP13: Nation Gone Dry by James Paddock and Richard Frei
 * MAP14: Shocker in Gloomtown by Brett Harrell and Björn Ostmann
 * MAP15: The Theory of Broken Circles by Björn Ostmann
 * MAP16: Tower in the Fountain of Sparks III (Episode Hub) by Xaser Acheron
 * MAP17: Steeple of Knives by Xaser Acheron
 * MAP18: Optional Bases Opposed by Paul DeBruyne
 * MAP19: Unbaited Vicar of Scorched Earth by Richard Frei
 * MAP20: Speedtraps for the Bee Kingdom by Richard Frei and Sarah Mancuso
 * MAP21: Bulldog Skin by Adam Woodmansey and Sarah Mancuso
 * MAP22: Bite by Matt Cibulas
 * MAP23: Tower in the Fountain of Sparks IV (Episode Hub) by Xaser Acheron
 * MAP24: Perhaps Now the Vultures by Richard Frei
 * MAP25: Unstable Journey by Brett Harrell
 * MAP26: Beneath a Festering Moon by Xaser Acheron
 * MAP27: by Richard Frei
 * MAP31: Fireking Says No Cheating by Josh Sealy, Sarah Mancuso and Boris Klimeš


 * MAP01: "Alien Jungle" by Stuart Rynn
 * MAP02: "Depth Charge" by Stuart Rynn
 * MAP03: "Twilit Jungle" by James Paddock
 * MAP04: "Lost City" by Sarah Mancuso
 * MAP05: "Mystproj" by Sarah Mancuso
 * MAP06: "Encased" by James Paddock
 * MAP07: "Free from My Shackles" by Eric Baker
 * MAP08: "The Night Guard" by James Paddock
 * MAP09: "Neighbouring Tribes" by Stuart Rynn
 * MAP10: "Noir" by Sarah Mancuso
 * MAP11: "Mystproj" by Sarah Mancuso
 * MAP12: "Mist at Dawn" by James Paddock
 * MAP13: "Scattered Ashes" by James Paddock
 * MAP14: "Enigma" by James Paddock
 * MAP15: "Geometry" by James Paddock
 * MAP16: "Mystproj" by Sarah Mancuso
 * MAP17: "Ominus" by Xaser Acheron
 * MAP18: "Birdsong" by Stuart Rynn listed as "Hell Jungle" due to 
 * MAP19: "Kashmoney Temple" by Xaser Acheron
 * MAP20: "Ether" by Sarah Mancuso
 * MAP21: "Stormwater" by James Paddock
 * MAP22: "Lurking" by Sarah Mancuso
 * MAP23: "Mystproj" by Sarah Mancuso
 * MAP24: "Petrichor (Blood of the Stone)" by James Paddock
 * MAP25: "Weather Warning" by James Paddock
 * MAP26: "Angry Science" by Xaser Acheron
 * MAP27: "Cruel" by Sarah Mancuso
 * MAP31: "Vinefort" by James Paddock
 * Ending screen: "Cruel" by Sarah Mancuso


 * Title screen: "Back to Saturn X" (James Paddock)
 * Intermission screen: "Intermission" (James Paddock, Sarah Mancuso, and Xaser)
 * Text screen: "Wait for Dawn" (Elric Sullivan)

Built-in demos
Episode 1 features three built-in demos. All require Doom II v1.9 to view them. The demo levels are:

Episode 2 also features three built-in demos for Doom II v1.9. The demo levels are:

Development
The development of the first episode was slowed down by the discovery of a then unknown bug, called the PWAD size limit bug. This bug occurred when the limited memory available to the lump stack, which is 64 kilobyte in size, caused issues as Back to Saturn X's PWAD needed more lumps than the 4046 that are available within this memory segment. On September 14, 2011, programmers Xttl and ConSiGno announced in a Doomworld forums to have an executable hack ready that increased the limit of the lump stack to 512 KB, allowing BTSX to load its resources fully. The released version however was split in two separate WAD files, mitigating the issue and allowing to be fully compatible with DOOM2.EXE, and removing the need for the modified executable, which was later released as Doom32.

Official add-on version
The release made available via the Doom Classic Unity port changes the names of the episodes and maps to remove the references to Guided By Voices.

Episode 1: Better Texturing with STARTAN-X
This version is technically an IWAD. The WADINFO lump identifies it as version 1.14i, and mentions "DO NOT DISTRIBUTE". The new list of level names:

Episode 2: "Big Towers", Says Xaser
The WADINFO lump identifies it as "Internal Hell Version 547385934785943758943574894", with a specified release date of "FUCKING NEVER LOL". The new list of level names: